I believe the dress must be appropriate for the occasion - regardless what kind of performance is being considered (ahem) I've worked with a couple of trios who do different stuff, so we dress differently.

One group does predominantly traditional scots material, usually mixed in with a light-hearted theme - so I (bodhran and chat) usually wear the kilt, either the phila-beag or phila-mhor ('scuse spelling), and the other bloke (guitar) wears basic black waistcoat and trousers with white shirt, while our female dulcimerist wears long tartan skirt and blouse.

The other group is more Cape Breton and trad/modern Canadian/Irish - there's a mix for you! - and the girls (fiddle/leader and keyboard) go on looking smart and dressy in long gowns, while I stick to dark trousers and a fancy coloured shirt.

Photos of both line-ups look good, and both groups feel that our outfits "fit" the presentations. Dingy sneakers and run-down jeans just don't measure up if the audience has paid good money to be entertained, unless it's done deliberately to make a point - but it had better be a good one!